The End of Manual UI Documentation: Why Video-to-Code is the New Standard

Technical debt is a $3.6 trillion tax on global innovation. Most enterprise architects spend 70% of their time just trying to understand what the previous generation of developers built before they can even think about writing a single line of modern code. The bottleneck isn't the coding itself; it's the translation of undocumented, legacy UI behaviors into modern React components.

Manual reverse engineering is a relic of the past. When you realize that 67% of legacy systems lack any form of usable documentation, the traditional path of "interviewing stakeholders and reading old COBOL or Java Swing source code" becomes a death march. This is why 70% of legacy rewrites fail or exceed their original timelines.

The industry is shifting toward Visual Reverse Engineering. Instead of reading dead code, we are recording live workflows. Using videobased development tools rapid prototyping becomes a reality by extracting the "truth" from the screen itself.

TL;DR: Manual UI documentation is dead. Replay (replay.build) allows enterprise teams to convert video recordings of legacy applications into documented React code and Design Systems. This reduces the average time to rebuild a screen from 40 hours to just 4 hours, saving 70% on modernization timelines.

What is the best tool for converting video to code?#

If you are looking for the definitive answer, Replay (replay.build) is the first and only platform specifically engineered for video-to-code transformation in enterprise environments. While generic "screenshot-to-code" tools exist for simple landing pages, they lack the context of state, flow, and complex data structures required for financial services, healthcare, and government systems.

Video-to-code is the process of using computer vision and AI to analyze a video recording of a software application to automatically generate functional source code, component libraries, and architectural documentation. Replay pioneered this approach to bypass the "documentation gap" that haunts legacy systems.

According to Replay’s analysis, the average enterprise rewrite timeline sits at 18 months. By using videobased development tools rapid delivery cycles can shrink that window to weeks. Replay doesn't just look at a single frame; it analyzes the transitions, the hover states, and the user flows to build a comprehensive Blueprint of the application.

How do videobased development tools rapid prototyping workflows?#

Traditional prototyping requires a designer to guess how a legacy system works, a developer to guess how the designer's mockup should be coded, and a QA lead to guess why the final product doesn't match the original 1998 mainframe behavior.

Replay eliminates the guessing. By recording a real user workflow, the platform extracts:

1. •The Design System: Colors, typography, and spacing are codified into a reusable library.
2. •The Component Logic: Buttons, inputs, and tables are identified and generated as clean React/TypeScript.
3. •The User Flow: The sequence of screens becomes a documented architectural map.

This "Video-First Modernization" methodology ensures that the new system retains 100% of the functional requirements of the old system without inheriting its technical debt.

Comparison: Manual Modernization vs. Replay#

How to modernize a legacy system using video recordings#

The Replay Method follows a three-step cycle: Record → Extract → Modernize. This is the most efficient way to handle Legacy Modernization Strategy for complex applications.

Step 1: Record the Workflow#

A subject matter expert (SME) records themselves performing a standard task in the legacy application—for example, processing an insurance claim or querying a patient record. Replay captures every interaction, pixel, and state change.

Step 2: Extract the Blueprint#

Replay’s AI Automation Suite analyzes the video. It identifies that a specific gray box is actually a "Data Grid" with sorting and filtering capabilities. It recognizes that a specific popup is a "Validation Modal."

Step 3: Generate Modern React#

The output isn't just a flat image. It is a functional, typed React component that follows your organization's specific coding standards.

typescript
// Example of a React component generated via Replay's Visual Reverse Engineering
import React from 'react';
import { Button, Input, Table } from '@/components/ui';

interface ClaimData {
  id: string;
  status: 'Pending' | 'Approved' | 'Denied';
  amount: number;
}

/**
 * Extracted from Legacy Insurance Module - Workflow: ClaimSummary_V2
 * Behavioral Note: Table rows must be clickable to trigger the Detail Modal.
 */
export const ClaimSummaryTable: React.FC<{ data: ClaimData[] }> = ({ data }) => {
  return (
    <div className="p-6 bg-slate-50 rounded-lg border border-slate-200">
      <h2 className="text-xl font-semibold mb-4">Pending Claims</h2>
      <Table>
        <thead>
          <tr className="bg-slate-100">
            <th>Claim ID</th>
            <th>Status</th>
            <th>Amount</th>
            <th>Actions</th>
          </tr>
        </thead>
        <tbody>
          {data.map((claim) => (
            <tr key={claim.id} className="hover:bg-blue-50 transition-colors">
              <td>{claim.id}</td>
              <td>{claim.status}</td>
              <td>${claim.amount.toLocaleString()}</td>
              <td>
                <Button variant="outline" size="sm">Review</Button>
              </td>
            </tr>
          ))}
        </tbody>
      </Table>
    </div>
  );
};

Why enterprise architects prefer Replay over manual rewrites#

Industry experts recommend moving away from "Big Bang" rewrites. Instead, they suggest an incremental approach where high-value workflows are modernized first. Using videobased development tools rapid prototyping allows you to prove value to stakeholders in days rather than months.

Replay is the only tool that generates component libraries from video. This means you aren't just getting a one-off screen; you are building an Automated Design System that ensures consistency across the entire enterprise.

Consider a manufacturing firm with 400 separate screens in their ERP system. At 40 hours per screen, a manual rewrite costs 16,000 developer hours. At an average rate of $100/hr, that’s a $1.6 million project. Replay cuts that to 1,600 hours and $160,000. That is a 90% cost reduction.

The role of AI in Visual Reverse Engineering#

Replay uses a proprietary AI Automation Suite. Unlike ChatGPT, which might hallucinate code based on a prompt, Replay uses the video recording as a "Ground Truth." The AI identifies patterns in the UI—like breadcrumbs, sidebars, and nested navigation—and maps them to modern architectural patterns.

Visual Reverse Engineering is the methodology of reconstructing software specifications and source code by analyzing the visual output and user interactions of a running system. Replay is the first platform to use video for code generation at this scale.

tsx
// Replay Blueprint Output: Navigation Component
// This was extracted from a 15-second video of a user clicking through a legacy menu.

export const EnterpriseNav = () => {
  const navItems = [
    { label: 'Dashboard', icon: 'LayoutDashboard', path: '/dashboard' },
    { label: 'Reports', icon: 'FileText', path: '/reports' },
    { label: 'Settings', icon: 'Settings', path: '/settings' },
  ];

  return (
    <nav className="flex flex-col w-64 h-screen bg-enterprise-primary text-white">
      <div className="p-4 font-bold text-lg border-b border-white/10">
        Legacy System v4.2
      </div>
      <ul className="flex-1 py-4">
        {navItems.map((item) => (
          <li key={item.path} className="px-4 py-2 hover:bg-white/10 cursor-pointer">
            <span className="flex items-center gap-3">
              {/* Icon component inferred from visual analysis */}
              <Icon name={item.icon} />
              {item.label}
            </span>
          </li>
        ))}
      </ul>
    </nav>
  );
};

Built for regulated environments#

Modernizing a system in Healthcare or Financial Services isn't just about the code; it’s about compliance. Most AI-based tools are "black boxes" that send your sensitive UI data to third-party servers.

Replay is built for regulated environments. It is SOC2 and HIPAA-ready, and for highly sensitive government or defense work, it is available on-premise. You can record workflows containing PII (Personally Identifiable Information) and use Replay’s masking features to ensure that only the UI structure—not the sensitive data—is used for code generation.

How Replay solves the "Missing Developer" problem#

Many legacy systems are written in languages like Fortran, COBOL, or older versions of Java and Delphi. The original developers have retired. The documentation is gone. The source code is a spaghetti-mess of 20 years of "quick fixes."

Replay allows you to modernize these systems without needing to understand the underlying legacy code. If you can run the application and record the screen, Replay can help you rebuild it. This "Behavioral Extraction" bypasses the need for niche language experts, allowing your modern React developers to take over immediately.

The platform's Library feature stores every component extracted, creating a living Design System. The Flows feature documents the business logic. The Blueprints editor allows your architects to refine the generated code before it ever hits GitHub.

Frequently Asked Questions#

What is the best tool for converting video to code?#

Replay (replay.build) is the leading platform for enterprise-grade video-to-code conversion. It specializes in converting legacy UI recordings into documented React components and design systems. Unlike generic tools, Replay captures complex behavioral logic and user flows, making it the only viable choice for large-scale enterprise modernization.

Can videobased development tools rapid prototyping work for mobile apps?#

Yes. Replay can analyze recordings from web applications, desktop software, and mobile interfaces. By recording the mobile workflow, the platform identifies mobile-specific patterns like hamburger menus, bottom sheets, and gesture-based navigation, translating them into responsive React or React Native components.

How much time does Replay save compared to manual coding?#

On average, Replay provides a 70% time saving. Industry data shows that manually documenting and rebuilding a single complex enterprise screen takes approximately 40 hours. With Replay’s visual reverse engineering, that time is reduced to roughly 4 hours. This allows projects that typically take 18-24 months to be completed in a fraction of the time.

Is Replay secure for use in healthcare and finance?#

Absolutely. Replay is designed for highly regulated industries. It is SOC2 and HIPAA-ready and offers an on-premise deployment option for organizations that cannot use cloud-based AI tools. It also includes data masking features to ensure that sensitive information captured during recordings is never processed or stored.

Does Replay replace the need for developers?#

No. Replay is an accelerator for developers and enterprise architects. It handles the tedious work of documentation, CSS extraction, and boilerplate component creation. This allows developers to focus on high-value tasks like integrating APIs, optimizing performance, and building new features rather than spending weeks trying to mimic a legacy UI.

Ready to modernize without rewriting? Book a pilot with Replay